Intermittant connection via 3G/4G at the Control end (TS-480 front panel)

[Vk7wh]

I am currently on holidays and been experimenting working my home rig remotely, using a TS-480 front Panel via both 3G and 4G at the control site with a pair of 1258 Mark IIs. I am using a Netcomm 3G/4G Wireless N150 Router 3GM2WN with a Telstra 4G USB Modem.

Having set everything up at home before I left the system worked OK apart from difficuly in initially establishing  a connection and at times, especially during weekends, drop outs on transmission due to poor upload speed. As I live in the countryside, this was not unexpected. The system is rock solid with an ADSL2+ connection.

The first site I tried on my trip I experienced very poor results which again were caused by an absolutely terrible 3G service with upload speeds varying from about 1Mbit/s to as low as 10Kbit/s!

When I tried the next location I visited I was encouraged to note that a fairly good 4G service was available. Download speed varied between 15Mbit/s down to a low of about 5Mbits/s and upload from a top of 7.5Mbits/s down to around 1Mbit/s. When connected, the service is again rock solid, with very good audio reports, but again I have trouble connecting. It usually takes from 2-3 minutes up to 10 minutes to get audio connected. I just have to keep switching it on and off until I get audio through. Sometimes changing band or using the PTT will trigger it. Once connected it remains so.

The only difference I can see in the Control RRC Set Up readings is when it is working:

SIP/STATUS = CONNECTING/TRANSFERRING
RTP STATUS = EXCELLENT (59)

During the time I am trying to connect:

SIP/STATUS = FAULTY (SEE BELOW)
RTP/STATUS = STALLED (20)

All other details on the setup page are the same in both conditions.

I can use the system as it is, however I would be very grateful is anyone has suggestion as to how I can overcome this annoying issue. My knowledge on networks, I am afraid, is reaching its limits.

Many thanks de Winston VK7WH

[dj0qn]

Winston,

You need to experiment around a lot with 3G/4G to get it working. In some cases, it was necessary
to change the router or even carrier to get it working well.

Here is a summary of tips that I send people to reduce bandwidth and optimize for 3G:

1) These two are important:
- audio quality to 0
- turn continuous RTP on

2) Play around with these 3 until you are satisfied:
- increase rx jitter buffer to min 10
- increase rx jitter delay to min 12
- audio packet size 20 or 40

3) Also, make sure that any serial port (COM1 and COM2 only) is turned off if not used,
and that any being used are set to the minimum bps necessary to handle the serial
communication. For example, use 4800 for CAT on a rig like the TS-480 and not a high
speed like 57600, since the higher speed is unnecessary.

73,
Mitch DJ0QN / K7DX

[Vk7wh]

Thanks Mitch for your suggestions. I forgot to mention that I did try increasing the rx buffer to 6 and the rx delay to 5 with no effect, but I  didn't try the higher figures you suggest. I will let you know how I get on with your suggestions. Incidently, the 2K-FA arrived just before I left on my holiday, so I haven't had a chance to fire it up yet. I will let you know how I go with the serial control.

Thanks again for your helpful suggestions, Mitch

Winston VK7WH